# Bit Error Probability Instead of Secrecy Rate Criterion to Enhance Performance for Secure Wireless Communication Systems

## TL;DR

This paper introduces a BEP-based power allocation method for physical layer security, demonstrating improved performance and lower power requirements compared to traditional secrecy rate criteria.

## Contribution

It proposes a novel BEP-based criterion for power allocation in physical layer security, addressing limitations of secrecy rate and enhancing system performance.

## Key findings

- BEP-based approach reduces power consumption by over 5dB.
- The method improves security performance for both legitimate and adversary users.
- A new outage probability definition is theoretically derived.

## Abstract

In this paper, we propose a new practical power allocation technique based on bit error probability (BEP) for physical layer security systems. It is shown that the secrecy rate that is the most commonly used in physical layer security systems, cannot be a suitable criterion lonely. Large positive values are suitable for the secrecy rate in physical layer security, but it does not consider the performance of the legitimate and adversary users. In this paper, we consider and analyze BEP for physical layer security systems because based on it, the performance of the legitimate and adversary users are guaranteed and it is needed to use lower power. BEP is calculated for the legitimate and adversary users and it is shown that BEP can be better criterion for performance evaluation of the physical layer security systems. Based on BEP, the optimum transmit power is obtained and a new definition for outage probability is proposed and obtained theoretically. Also, the proposed approach is applied for adversary users with unknown mode and the cooperative adversary users. Simulation results show that the proposed method needs more than 5dB lower power for different scenarios.